1. Field of the Invention
The invention relates to an image recording apparatus such as printer which performs a print on mediums such as bank book and the like with different thicknesses; in particular, printer which keeps a fixed interval between print head and medium according to the different thicknesses of the mediums.
2. Related Background Art
In previous printer, in order to keep an interval between print head and print medium in a fixed value, an automatic paper thickness judgment mechanism was provided. The automatic paper thickness judgment mechanism has a guide plate fixed on a carriage as contacting with surface of the print medium. According to a self weight of the print head, the guide plate presses the print medium. When a thicker print medium is fed, the guide plate rises due to thickness of the print medium, thus a fixed interval is set between surface of the print medium and front edge portion of the print head. The printer provided with the automatic paper thickness judgment mechanism has been disclosed in Japan utility model publication No. 2542947 and etc.    Patent document 1: Japan utility model publication No. 2542947.
However, in the printer disclosed in the patent document 1, the carriage carrying the print head can rotate around a carriage shaft as a center. When a thicker print medium is fed into lower side of the guide plate, the carriage rotates around the carriage shaft and expands an interval with the print medium. Therefore, an angle formed between the front edge portion of the print head and the print medium becomes inclined so as to make printed character and the like deform.